Recently, studies on medical materials utilizing various polymeric materials have been in progress and their application to membranes for an artificial kidney, membranes for a blood plasma separator, catheters, stents, membranes for an oxygenator, artificial blood vessels, membranes for preventing synechia, artificial skin, or the like is expected. In this case, synthetic polymeric materials that are foreign materials to living bodies are used in contact with biological tissues or body fluids such as blood. Accordingly, it can be desirable for the medical material to have biocompatibility. Although the biocompatibility required for the medical material varies depending on its purpose or usage, characteristics (antithrombogenicity) such as inhibition of a blood coagulation system, inhibition of adhesion and activation of platelets, and inhibition of activation of a complement system are expected as the medical material used as a material coming into contact with blood.
In general, imparting of the antithrombogenicity to a medical apparatus is performed through a method of coating a base material constituting the medical apparatus with an antithrombotic material, or a method of fixing the antithrombotic material onto the surface of the base material.
For example, JP-A-4-152952 discloses membranes for artificial organs or medical apparatuses of which the surfaces are provided with synthetic polymers simultaneously satisfying the biocompatibility such as inhibition of adhesion and activation of platelets and an effect of inhibition of activation of a complement system, and affinity for tissues in living bodies, and which are used in contact with tissues or blood in living bodies.